A heat therapy device of this kind is known from DE 20 2005 021 580 U1. The heat therapy device comprises a care unit having a lying surface for supporting an infant. Furthermore, a hood is provided which is moveable between a closed position covering the care unit and an opened position clearing the top of the care unit. Furthermore, a radiation heating is provided which can irradiate the lying surface of the care unit in the opened position of the hood. In addition, a convection heating is provided which serves to maintain the temperature within the care unit at a desired level when the hood is in the closed position. The operation of the radiation heating and the convection heating is controlled by control units. The control units are arranged such that the convection heating is controlled as a primary heating when the hood is closed and that the operation of the radiation heating is controlled as primary heating when the hood is in the opened position. In addition it is mentioned that the radiation heating may be heated up before the beginning of an opening step of the hood, in order to reach the desired temperature faster after the hood is opened. From U.S. 2002/0161276 A1 a heat therapy device is known which is arranged to pre-heat the convection heating before the hood is closed.
Such heat therapy devices are also referred to as “hybrids” which can operate as an incubator in the closed position of the hood and can be operated in the opened position of the hood for open therapy care.
Analytical investigations of the heat balance of an infant during the transition from the closed care to the open care mode or vice versa show that the infant cools off during opening of the hood because the air temperature and the air humidity are decreasing rapidly and because the warm, protecting walls of the hood are removed.
EP 1 124 403 B1 describes a heat therapy device. If the hood is in the closed position (incubator operation) the radiation heating is automatically switched off. Conversely, the convection heating is automatically switched off when the hood is lifted up. Furthermore, the radiation heating is, when it is initially switched on, operated with increased power for a given heating-up period, which increased power is larger than 100% of the nominal power of the lamp. This is disadvantageous because this reduces the lifetime of the radiation heating.